Crystal orientation of epitaxial α-Ta(110) thin films grown on Si(100) and Si(111) substrates by sputtering

We have prepared Ta thin films oil Si(100) and Si(111) substrates by increasing the substrate temperature from room temperature (RT) to 500 degrees C. using, an ultrahigh-vacuum dc magnetron sputtering system.. The obtained film crystallinities were evaluated by X-ray diffraction and X-ray pole figure analyses. It was found that the crystal phase of the prepared Ta films transforms gradually from the beta-Ta phase to the alpha-Ta phase with increasing substrate temperature, and the epitaxial growth of the alpha-Ta(110) plane was realized at substrate temperatures of 400 degrees C on Si(100) and 200 degrees C oil Si(l 11). In addition, it was also clarified that the alpha-Ta(110) films arc grown epitaxially in a twin state on Si(100), while they are grown epitaxially in a triplet state oil Si(111).